Abstract: A machine tool capable of eliminating a laborious attachment/detachment work of a cover member is provided. The machine tool includes a door device 5 having a first door 6 to cover a machining-area opening 3e when machining a workpiece and a second door 7 to cover the machining-area opening 3e when not machining the workpiece and formed to be visible an inside thereof, in which the first door 6 and the second door 7 are arranged in a movable manner between a position-in-use covering the machining-area opening 3e and a position when opened opening the machining-area opening 3e.

Abstract: Tool rest enabling tool holders to be installed quickly and easily onto, and precisely aligned with respect to, the tool-rest turret. The turret (30) is a rotatably supported, polygonal columnar component onto the peripheral surface of which the tool holders are detachably/reattachably mounted. A first key (32), second key (33), and third key (34) having parallel side engagement surfaces (32a), (33a), (34a) are formed protruding from the tool holder mounting surfaces (30a) on the outside of the turret 30. The engagement surfaces (32a), (34a) of the first key (32) and third key (34) are parallel to each other, and the engagement surfaces (33a) of the second key (33) are perpendicular to the engagement surfaces (32a) of the first key (32). Key slots in which the keys (32), (33), (34) are inserted and which engage the engagement surfaces (32a), (33a), (34a) of the keys are formed in the turret mounting face.